Elevation gear for a firing device for jet-propelled guided missiles

ABSTRACT

The elevation gear is disengageably mounted on a traversable sub-structure, and includes a threaded spindle rotatably mounted on a support and two plungers mounted in laterally spaced relation on the support for displacement upwardly and downwardly, the plungers serving as supports for the firing device. Abutments on the support between the plungers are disengageably cooperable with the firing device to serve as a pivot axis for elevational displacement of the firing device. A play-free transmission interconnects the spindle and the plungers and is operable, responsive to rotation of the spindle, to displace the plungers simultaneously in respective opposite directions. The transmission comprises two nuts threaded on the spindle and each connected to a respective lever, with each lever engaging the lower end of a respective plunger. The free ends of the levers are inclined and ride on respective rollers so that, when the nuts are displaced longitudinally by rotation of the spindle, the free ends of the levers are moved upwardly or downwardly. The plungers have rollers at their lower ends engaging the respective levers, and the upper ends of the plungers engage rollers on the firing device. One of the plungers is spring loaded. An elevation indicator is articulatedly connected to one of the nuts.

United States Patent Pfister et al.

Aug. 29, 1972 [54] ELEVATION GEAR FOR A FIRING DEVICE FOR .IET-PROPELLED GUIDED MISSILES [72] Inventors: Franz Pfister, l-lochstadt; Ernst Albrecht, Unterhaching; Josef Durner, Ottobrunn; Eicke Maus, Solingen, all of Germany [73] Assignee: Messerschmitt-Bolkow-Blohm Gesellschaft mit beschrankter Haftung, Munich, Germany 22 Filed: April 27,1970

21 Appl.No.: 32,151

[30] Foreign Application Priority Data Primary Examiner-Stephen C. Bentley Attorney-McGlew and Toren ABSTRACT The elevation gear is disengageably mounted on a traversable sub-structure, and includes a threaded spindle rotatably mounted on a support and two plungers mounted in laterally spaced relation on the support for displacement upwardly and downwardly, the plungers serving as supports for the firing device. Abutments on the support between the plungers are disengageably cooperable with the firing device to serve as a pivot axis for elevational displacement of the firing device. A play-free transmission interconnects the spindle and the plungers and is operable, responsive to rotation of the spindle, to displace the plungers simultaneously in respective opposite directions. The transmission comprises two nuts threaded on the spindle and each connected to a respective lever, with each lever engaging the lower end of a respective plunger. The free ends of the levers are inclined and ride on respective rollers so that, when the nuts are displaced longitudinally by rotation of the spindle, the free ends of the levers are moved upwardly or downwardly. The plungers have rollers at their lower ends engaging the respective levers, and the upper ends of the plungers engage rollers on the firing device. One of the plungers is spring loaded. An elevation indicator is articulatedly connected to one of the nuts.

11 Claims, 2 Drawing Figures Patented Aug. 29, 1972 3,687,005

2 Sheets-Sheet 1 INVENTORS Franz Pfister Ernst Albrecht Josef Durner B H Eicke Maus y Zf ATTORNEYS Patented Aug. 29, 1972 2 Sheets-Sheet 2 INVENTORS rtr m 5 r fimu PwD Z m nuts U O rn Fr E icke Muus ATTORNEYS y Md! BACKGROUND OF THE INVENTION Firing devices for jet-propelled guided missiles are necessary when missiles are to be guided into a target semi-automatically by the so-called line-of-sight method. In this method, a gunner has only to aim the firing device, which is provided with an optical sight and an automatic locating means, very accurately on the target before the take-off of the missile and during its flight, or, respectively, to track the missile exactly on a moving target. The guiding signals, which maintain the missile to be guided on a straight line connecting the gunners eye with the target, are influenced by movements of the firing device about the vertical and transverse axes. The deviation of the missile from the straight line-of-sight is automatically determined by the locating or the direction-finding means, and is a measure of the restoring guiding command to be transmitted to the missile.

it will be clear that such a firing device must meet very high requirements. For example, its aiming gears must work so accurately that the missile, upon take-off, comes into the pick-up range of the direction finding means immediately as it leaves the firing device, as otherwise guiding of the missile is not possible. Since, as a rule, infrared goniometers are used as the direction finding means, this pick-up range is relatively small. Additionally, it must be assured that the firing device does not change its position, which has been adjusted before the take-off of the missile, despite displacement of the center of gravity of the firing device as a result of the missile leaving the device. Furthermore, the elevation setting gear must not be influenced in its adjustment by tilting moments occurring as the missile takes off.

Consequently, in addition to play-free operation of such a mechanism, it must be assured that considerable forces can be absorbed, and that any manufacturing tolerances and wear can be compensated. On the other hand, for the tracking movement of the firing device and which influences the guiding signal generation, the elevation gear as well as the traversing gear must be adjustable easily and continuously. Furthermore, the elevation gear must be lightweight and compact, so that the weight of the firing device and its substructure is maintained as low as possible.

An elevation gear, for a firing and guiding device of the above-mentioned kind, is known from German Pat. No. 1,266,665, and consists of a play-free, self-locking worm gear which is movable by a knob through the medium of two bevel gears. The worm gear, which comprises a worm and a worm gear segment, is contained in a housing having an abutment for the detachable retention of the firing device, and which is pivoted during the elevation movement of the firing device. Apart from the disadvantageously large opening in the firing device involved by such retention, and which, for example, is almost impossible to keep clean during use, such an elevation gear has a relatively great structural height and is expensive to manufacture.

For tactical reasons, however, a substructure for supporting a firing device should have as low a height as possible. The making of the gear chain playfree is effected at the expense of easy motion in operation. Furthermore, considerable difiiculties are involved in absorbing the tilting moments transmitted to the substructure, through the elevation gear, upon take-off of the missile, and without slight displacements of the firing device. Due to the relatively large lever arms, the least displacements already result in signals which influence the guiding of the missile.

SUMMARY OF THE INVENTION This invention relates to elevation gears for setting the elevation of a firing device for remotely controlled jet-propelled guided missiles and, more particularly, to such an elevation gear which is free of the above-mentioned disadvantages, comprises a few simple components, is inexpensive to manufacture, is easily movable in a play-free and continuous manner, has a self-enclosed form of small dimensions, and is connectable with the firing device in a simple manner.

Based upon an elevation gear for a firing device for jet-propelled guided missiles which is disengageably mounted on a traversable substructure, the problem presented is solved, in accordance with the invention, by providing two plungers which are displaceable upwardly and downwardly in respective opposite directions simultaneously, and which serve as bearings for the firing device. These plungers are simultaneously and conjointly displaceable in respective opposite directions by rotation of a threaded spindle through the medium of a play-free transmission interconnecting the spindle and the plungers. An abutment means for the firing device is arranged between the. plungers and serves as a pivot axis for movement of the firing device in elevation.

The plungers are displaceable by inclined planes movable in opposite directions parallel to the longitudinal axis of the threaded spindle, and the transmission preferably comprises a lever transmission associated with each plunger, with the lever transmissions being arranged in mirror symmetry on opposite sides of the threaded spindle.

The lever transmissions are connected with respective nuts positioned in longitudinally spaced relation on the threaded spindle, and arranged in sleeves which, in turn, carry respective pivot pins extending transversely of the longitudinal axis of the spindle and connected to a lever of the associated transmission. The free end of each lever has a roll-off surface determining the vertical displacement of the associated plunger.

Such a lever transmission in an elevation gear for a firing device is characterized by great simplicity and sturdiness and, at the same time, operates much more accurately than does a worm gear driven through the medium of bevel gears. Another advantage is the very small space requirement and the freedom of maintenance of such a transmission. Due to the simple form of the force-transmitting members, the setting means of the firing device can be maintained free of transverse forces, so that, if the firing device is incorrectly handled, jamming cannot occur.

In contrast to an approximately punctiform contact between individual force-transmitting members in a worm gear transmission, the elevation gear embodying the invention presents, at its roll-ofi surfaces, relatively large linear contact faces, so that the unit pressures can be kept relatively small. Additionally, it is simpler, in terms of production engineering, to produce the rollof? surfaces determining the vertical displacement in the form of inclined planes having a predetermined slope, and which render possible an exact and continuous adjustment. By the use of a lever transmission, therefore, the known advantages of the latter are utilized, such as low energy requirement and low friction, to fulfill the high requirements to be met by an elevation gear for firing devices for guided missiles. By the arrangement of the levers parallel to the longitudinal axis of the spindle, the structural height of the transmission can be kept surprisingly small.

In accordance with another feature of the invention, the roll-off face of each lever, which determines the vertical displacements of the associated plunger, slides on a roll through the medium of a surface adjacent the roll-off surface supporting the associated plunger at the free end of the lever. Each lever is approximately L- shaped and presents, at its smaller leg which is remote from the pivot point, the roll-ofi' face determining the vertical displacement, and correlated with the associated plunger, and another roll-off surface extending substantially parallel to the roll-off surface supporting the associated plunger and effecting change-over of the respective plunger from the rest position to the working position. In accordance with a further feature of the invention, one of the plungers is spring-loaded and, by means of the single spring-loaded plunger, the transmission play, as well as the play between the elevation gear and the firing device, is eliminated. Finally, the threaded spindle extends transversely to the traversing axis of the firing device.

As a further feature of the invention, each sleeve terminates, at its end remote from the associated nut, in a supporting jib of approximately semi-circular crosssection, the two supporting jibs being oppositely directed, and each sleeve is formed with a recess contiguous to the portion thereof receiving the associated nut. By this arrangement, any incidental transverse forces can be transmitted through the supporting jibs to the respective recesses, thus preventing canting of the nuts which are threadedly engaged with the threaded spindle.

The invention elevation gear has a further feature in that, at one of the pivot pins, a thrust rod is articulated to extend parallel to the associated lever, and the free end of this lever is articulated to a second lever which is pivotally mounted and connected with a sleeve carrying a pointer. The deflection of the pointer is a measure of the particular displacement of the plungers, and thus a measure of the elevation which has been set. In addition, the pointer permits easy reading of the mid-position of the elevation gear.

An object of the invention is to provide an improved elevation gear for a firing device for remotely controlled jet-propelled guided missiles.

Another object is to provide such an elevation gear which comprises a few simple components and is inexpensive to manufacture.

A further object is to provide such an elevation gear which moves easily in a play-free and continuous manner.

Another object of the invention is to provide such an elevation gear which has a self-enclosed form of small dimension.

A further object of the invention is to provide such an elevation gear which is disengageably connectable with the firing device in a simple manner.

Another object of the invention is to provide such an elevation gear which is disengageably mountable on a traversable sub-structure.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. I is an exploded perspective view of an elevation gear embodying the invention as arranged in a substructure; and

FIG. 2 is a perspective view of the actual elevation gear without its housing.

DESCRIPTION OF THE PREFERRED ENIBODIMENT Referring to the drawings, an elevation gear 4, embodying the invention, is mounted in the housing 1 forming the head of a sub-structure 3 which may be, for example, a tripod only two legs of which are visible in FIG. I. A firing device 5 is detachably connectable with the head of the sub-structure 3. Firing device 5, which is only partly illustrated, is designed for guided, jetpropelled missiles and is equipped with an optical sight (not shown) and a direction finding means (also not shown). To effect disengageable connection of firing device 5 and sub-structure 3, the top side 7 of housing 1 is provided with a two-part abutment 8 which forms the pivot axis for elevation of firing device 5. Abutments 8 are embedded in projections 9 forming a part of housing 1, and have knife edges 10 engageable in correspondingly formed bearings 11 on the underside of firing device 5.

As illustrated in greater detail in FIG. 2, elevation gear 4 includes a threaded spindle 14 having an operating knob 13, and the rotary movement of spindle 14 is transmitted, in a manner which will be described, through nuts 15 and 16 to respective levers l9 and 20. Levers 19 and 20 are arranged in mirror symmetry with the longitudinal axis of spindle l4, and each lever is formed as an angle member. The levers cooperate with respective vertically displaceable plungers 21 and 22, and each lever has two legs 25 and 26 which define an obtuse angle which, as illustrated in the drawing, faces upwardly.

As the two transmissions of the elevation gear are identical in mirror-symmetrical arrangement, the details of the elevation gear will be described only with reference to the transmission which is at the front as viewed in FIG. 2, and which includes the lever 19. Lever 19 is operatively connected with spindle 14 through a pivot pin 30 which extends normal to the longitudinal axis of spindle l4 and which is provided at an extension 28 of a sleeve, described more fully hereinafter, receiving nut 16. Lever 19 is arranged, in a manner not shown in detail, for oscillation on pivot pin 30. The free end of lever 19 which is remote from the bearing point, that is, the free end of leg 26, presents a plane bearing surface 32 on which plunger 21 is supported through the medium of a roller 33. The surface of leg 26 facing away from the bearing point is designed as a roll-off surface 34 through the medium of which lever 19 rests on a roller 37 rotatably mounted in a yoke 35 fixed in the housing and which surface, as a function of its inclination, determines the vertical displacement of firing device 5 responsive to rotation of 5 spindle 14, as described more fully hereinafter. The surface 18 of leg 26 extending parallel to roll-off surface 34 is also designed as a sliding surface to bring the associated plunger from its position of rest, which has not been shown in FIG. 2, into the illustrated operative position. Roll 37 is rotatably supported on a bearing bolt or pin 38 secured in yoke 35.

Plungers 21 and 22 are designed as hollow cylindrical bodies, and each body has a roller 33 rotatably mounted at one end thereof. Plunger 21 is mounted elastically and, for this purpose, a bearing element 44 is provided at the lower end of plunger 21 and carries rotatably a roller 33. A spring 48 extending through the interior of plunger 21 has one end engaged with bearing element 44 and its other end engaged on an inner surface of the plunger or, respectively, on a pressure element 45. Thereby, plunger 21 can move relatively to bearing element 44 and, for this movement, the openings in plunger 21, embracing the rotation axle of roller 33, are designed as oblong slots 50. As best seen in FIG. 1, plungers 21 and 22 are guided in housing 1 through the medium of cylinders or cylindrical bushings S1 and 52, respectively.

Nuts and 16 are positioned in the end faces of the respective sleeves 53 and 54 which terminate, at the ends remote from the associated nuts, in oppositely directed supporting jibs 58 and 59, respectively, of approximately semi-circular cross-section. Each sleeve is formed, contiguous to the portion mounting the associated nut 15 or 16, with a recess 56, 57 respectively, which recesses serve as abutments for the actual supporting surfaces of the supporting jibs 58 and 59, respectively. With this arrangement, the transverse forces transmitted through plungers 21 and 22 and through levers 19 and to sleeves 53 and 54, and thus to nuts 15 and 16, are transmitted over supporting jibs 58 and 59 to the respective recesses 56 and 57. Thereby canting of the nuts, which are threadedly en gaged with spindle 14, is prevented.

On one side of elevation gear 4, namely on that side which is toward the front in FIG. 2, there is articulated on pivot pin 30, between lever 19 and nut 16, a thrust rod 61 which extends in the direction of lever 19. The free end of thrust rod 61 is articulatedly connected with a pivotally mounted lever 63 secured to which is a horizontally extending sleeve 65 provided with a pointer 64. Pointer 64 traverses an opening (not shown) in housing 1, illustrated in FIG. 1, and is correlated with a visible and feelable mark 68 which, for example, indicates the mid-position of the elevation gear. Upon rotation of spindle 14, thrust rod 61 moves pointer 64 through lever 63 so that, for example, the deviation from the mid-position, readable from the outside, is a measure of the angular displacement in elevation of the firing device.

Referring again to FIG. 1, in addition to the already described abutments 1 1, firing device 5 has recesses 69 and 70 which match the ends of the plungers 21 and 22. Each recess receives a bearing element 73 and 74, respectively, rotatably mounting a respective roller 71 and 72, and the bearing elements are held in firing device 5 by split rings 75. Rollers 71 and 72 form the bearing members engaging the plungers 21 and 22.

The elevation gear operates in a manner which will now be described. To connect firing device 5 with housing 1 of substructure 3, plungers 21 and 22 must be brought, by rotation of knob 13, into the already mentioned rest position. In so doing, the elastically mounted plunger 21 is moved over and beyond the highest position, which has not been illustrated, and in which projection 17 of lever 19 is moved over roller 37 and disengages this roller. Roller 33 rolls on the sliding surface 18, opposite the roll-off surface 34, into the obtuse angle defined by legs 25 and 26. Plunger 22, however, is supported in its rest position by its associated roller 37 only, since the associated lever 20 has been disengaged from the roller 37. In the rest position, plungers 21 and 22 occupy their lowest position, which has not been shown in the drawings.

After such retraction of plungers 21 and 22, firing device 5 can be connected with substructure 3 by hooking abutments l1 beneath knife edges 10 of the pivot axes 8. By reversing the direction of rotation of knob 13, levers l9 and 20 are now moved in the opposite direction until each plunger again occupies its highest position in which projection 17 of lever 19, for example, is vertically aligned above the axis of roll 37. Lever 20 correspondingly is moved into operative engagement with plunger 22. The firing device is now connected with the elevation gear, and this has been indicated to the gunner by the perceptible resistance to movement caused by projections 17. Upon continued rotation of spindle 14, levers 19 and 20 are moved back into the position shown in FIG. 2.

In their operative position, plungers 21 and 22 engage the abutments provided by rollers 71 and 72 in firing device 5. Through the lever mechanism, spring 48 biases the firing device against the knife edges 10 of pivot axes 8, as well as the nuts 15 and 16 against the flanks of the thread of spindle 14. Consequently, play between nuts 15 and 16 and spindle 14, as well as play between elevation gear 4 and firing device 5, is eliminated.

The gunner now operates spindle 14 through the medium of knob 13 until pointer 64 coincides with the mark indicating the mid-position of the elevation gear. For the sake of completeness, it should be mentioned that relatively large magnitudes of deviations from the mid-position, due, for example, to irregularities of the ground, are compensated by the gunner by adjustment of the legs of the substructure rather than by adjustment of the elevation gear.

Firing device 5 is now ready for guiding operation. During the actual guiding operation, plungers 21 and 22 are moved upwardly and downwardly in respective opposite directions and conjointly and simultaneously, by rotation of spindle 14 either clockwise or counterclockwise. Due to the above described connection between firing device 5 and elevation gear 4, the firing device 5 follows the movements of the plungers in the manner of a balance beam, that is, firing device 5 is pivoted about the elevation axis in proportion to the actual sighting process.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; knife edge abutment means on said support between said plungers and cooperable with corresponding bearings of the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions.

2. An elevation gear, as claimed in claim 1, in which said transmission comprises a pair of lever mechanisms each operatively associated with a respective plunger; said lever mechanisms being arranged in mirror symmetry on respective opposite sides of said spindle.

3. An elevation gear, as claimed in claim I, in which said spindle extends transversely relative to the traversing axis of said substructure.

4. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; said transmission comprising a pair of lever mechanisms each operatively associated with a respective plunger; said lever mechanisms being arranged in mirror symmetry on respective opposite sides of said spindle; a pair of nuts threaded on said spindle in axially spaced relation from each other and each connected to a respective lever mechanism; each nut being fixed in a respective sleeve; a respective pivot pin carried by each sleeve and extending transversely relative to the longitudinal axis of said spindle; each lever mechanism including a respective lever articulated on a respective pivot pin and having, on its free end, a rolloff surface cooperable with the associated plunger to effect the displacement of the associated plunger.

5. An elevation gear, as claimed in claim 4, including a respective roller engaging the roll-off surface of each lever.

6. An elevation gear, as claimed in claim 5, in which each lever has, at its free end, a second surface adjacent the associated roll-off surface; each plunger being supported on the second surface of a respective lever.

7. An elevation gear, as claimed in claim 6, in which each lever is substantially L-shaped including a long leg and a short leg, the short leg being remote from the pivot point of the associated lever; the associated rolloff surface and the associated second surface being formed on the short leg of each lever; the short leg of each lever having a second roll-off surface extending substantially parallel to the first-mentioned roll-off surface and effecting change-over of the associated plunger from the rest position to the operating position of the associated plunger.

8. An elevation gear, as claimed in claim 4, in which each nut is mounted in a first end of the respective sleeve; the second end of each sleeve terminating in a supporting jib of substantially semi-circular crosssection, said supporting jibs being oppositely directed; each sleeve being formed, contiguous to its first end, with a recess receiving the supporting jib of the other sleeve.

9. An elevation gear, as claimed in claim 4, including a thrust rod pivoted on one of said pivot pins and extending parallel to the associated lever; a pivotally mounted second lever articulated to the free end of said thrust rod; a sleeve fixed to pivot with said second lever about the pivotal axis thereof; and a pointer carried by said sleeve, the deflection of said pointer indicating the respective stroke of said plungers and thus the elevation set by rotation of said threaded spindle.

10. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; said transmission including two inclined planes arranged on opposite sides of said spindle for movement parallel to the longitudinal axis of said spindle, each inclined plane engaging a respective plunger; said inclined planes, responsive to rotation of said spindle, being moved in respective opposite directions parallel to said spindle.

M. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; one of said plungers being spring-loaded. 

1. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; knife edge abutment means on said support between said plungers and cooperable with corresponding bearings of the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions.
 2. An elevation gear, as claimed in claim 1, in which said transmission comprises a pair of lever mechanisms each operatively associated with a respective plunger; said lever mechanisms being arranged in mirror symmetry on respective opposite sides of said spindle.
 3. An elevation gear, as claimed in claim 1, in which said spindle extends transversely relative to the traversing axis of said substructure.
 4. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, Of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; said transmission comprising a pair of lever mechanisms each operatively associated with a respective plunger; said lever mechanisms being arranged in mirror symmetry on respective opposite sides of said spindle; a pair of nuts threaded on said spindle in axially spaced relation from each other and each connected to a respective lever mechanism; each nut being fixed in a respective sleeve; a respective pivot pin carried by each sleeve and extending transversely relative to the longitudinal axis of said spindle; each lever mechanism including a respective lever articulated on a respective pivot pin and having, on its free end, a roll-off surface cooperable with the associated plunger to effect the displacement of the associated plunger.
 5. An elevation gear, as claimed in claim 4, including a respective roller engaging the roll-off surface of each lever.
 6. An elevation gear, as claimed in claim 5, in which each lever has, at its free end, a second surface adjacent the associated roll-off surface; each plunger being supported on the second surface of a respective lever.
 7. An elevation gear, as claimed in claim 6, in which each lever is substantially L-shaped including a long leg and a short leg, the short leg being remote from the pivot point of the associated lever; the associated roll-off surface and the associated second surface being formed on the short leg of each lever; the short leg of each lever having a second roll-off surface extending substantially parallel to the first-mentioned roll-off surface and effecting change-over of the associated plunger from the rest position to the operating position of the associated plunger.
 8. An elevation gear, as claimed in claim 4, in which each nut is mounted in a first end of the respective sleeve; the second end of each sleeve terminating in a supporting jib of substantially semi-circular cross-section, said supporting jibs being oppositely directed; each sleeve being formed, contiguous to its first end, with a recess receiving the supporting jib of the other sleeve.
 9. An elevation gear, as claimed in claim 4, including a thrust rod pivoted on one of said pivot pins and extending parallel to the associated lever; a pivotally mounted second lever articulated to the free end of said thrust rod; a sleeve fixed to pivot with said second lever about the pivotal axis thereof; and a pointer carried by said sleeve, the deflection of said pointer indicating the respective stroke of said plungers and thus the elevation set by rotation of said threaded spindle.
 10. An elevation gear, for setting the elevation of a firing device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; said transmission including two inclined planes arranged on opposite sides of said spindle for movement parallel to the longitudinal axis of said spindle, each inclined plane engaging a respective plunger; said inclined planes, responsive to rotation of said spindle, being moved in respective opposite directions parallel to said spindle.
 11. An elevation gear, for setting the elevation of a firiNg device for remotely controlled, jet propelled guided missiles, disengageably mounted on a traversable substructure, said elevation gear comprising, in combination, a support; a threaded spindle rotatably mounted on said support; two plungers mounted in laterally spaced relation on said support for displacement upwardly and downwardly, and serving as supports for the firing device; abutment means on said support between said plungers and cooperable with the firing device to serve as a pivot axis for displacement, in elevation, of the firing device; and a play-free transmission interconnecting said plungers and said spindle and operable, responsive to rotation of said spindle, to displace said plungers, conjointly and simultaneously, in respective opposite directions; one of said plungers being spring-loaded. 